Why Lack of Sleep Has a Deleterious Effect on the Brain

Sleep deprivation can trigger a seizure. To shorten their stay in the hospital, the patients stayed up all night to evoke one. Researchers asked them several times over the course of the night to identify a number of images as fast as they could. These were six images of celebrities, famous landmarks, and animals. The implanted electrodes meanwhile recorded the combined firing of 1,500 neurons, which includes the brain activity of all 12 volunteers. Specific attention was given to the temporal lobe, responsible for memory and processing sensory information, including visual perception.

This exercise was performed on 24 separate occasions. As the night wore on and patients got drowsier, their ability to name the pictures quickly slowed, as did their neural activity. The neurons fired weakly and transmissions to other parts of the brain moved more slowly. As a result, participant response-time lagged.